State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Biomed Microdevices. 2020 Feb 15;22(1):18. doi: 10.1007/s10544-020-0475-9.
Centrifugal droplet-based microfluidic devices have been applied to biomedical analysis and diagnostics recently. However, in centrifugal droplet-based microfluidic devices, droplets are tightly packed (i.e., the oil film between neighbouring droplets is thin). Therefore, droplet coalescence usually occurs especially during thermal incubation process. To preserve individual droplets in the devices, we report a new design for monodisperse droplet generation and storage that exploits a centrifugal configuration for droplet emulsification and oil-storage structures (OSSs) for regulation of the thickness of oil film between neighbouring droplets. The centrifugal emulsifier was well designed to ensure uniform droplet generation. Meanwhile, the OSSs could store oil during centrifugal emulsification while release oil before thermal incubation, which "loosen" tightly packed droplets to prevent droplets from coalescing. In this paper, the working process of OSS was analysed, and its shape and size were optimized. Then, the optimized OSSs were integrated into a centrifugal emulsifier for droplet digital loop mediated isothermal amplification (ddLAMP) by which detection of JAK2 V617F mutation within myeloproliferative neoplasms with a dynamic range of 10 to 10 copies per μL was achieved. We anticipate that the simplicity and robustness of our system make it attractive as an inexpensive and easy-to-operate device for DNA amplification, particularly applicable in point-of-care settings.
最近，基于离心的液滴微流控装置已被应用于生物医学分析和诊断。然而，在基于离心的液滴微流控装置中，液滴被紧密地包装在一起（即相邻液滴之间的油膜很薄）。因此，液滴聚结通常会发生，特别是在热孵育过程中。为了在设备中保留单个液滴，我们报告了一种新的设计，用于单分散液滴的生成和存储，该设计利用离心配置进行液滴乳化，以及油存储结构（OSS）来调节相邻液滴之间油膜的厚度。离心乳化器设计精良，可确保均匀的液滴生成。同时，OSS 可以在离心乳化过程中储存油，而在热孵育之前释放油，从而“松开”紧密包装的液滴，防止液滴聚结。在本文中，分析了 OSS 的工作过程，并对其形状和尺寸进行了优化。然后，将优化后的 OSS 集成到离心乳化器中，用于液滴数字环介导等温扩增（ddLAMP），从而可以在 10 到 10 拷贝/μL 的动态范围内检测骨髓增生性肿瘤中的 JAK2 V617F 突变。我们预计我们的系统的简单性和鲁棒性使其成为一种具有吸引力的廉价且易于操作的 DNA 扩增设备，尤其适用于即时护理环境。
